Guard for switch boxes



April 23, 1929. M. P. LUTHER GUARD FOR SWITCH BOXES 1 Filed March 21, 1927 Ewe/27??? MART/N' F. L UTHER.

Patented Apr. 23, 1.929. d UNITED STATES FATE-ill QFFHCE- MARTIN P. LUTHER, OF CHICAGO, lLLINOIS, ASSIGNOR TO 31H SAFETY SFTITCI-I 00., OF CHICAGO, ILLINOIS, A CORPORATIGN OF ILLENQIS.

GUARD FOR SWITCH BOXES.

such persons cannot come into contact with any live portions or connectors of the switch. The safety wall may be removed from its normal position by authorized or experienced persons and a precautionary means are provided which will prevent such persons accidentally closing the box without replacing the guard or safety wall, It is also impossible for inexperienced persons to meddle with. the switch mechanism or cut in the circuit while the cover or lid of the box is open.

It is an object of my invention to provide a structure such as alcove outlined, that is simply made. is economical in production, and is dependable and eflicient in operation. I prefer to carry out my invention and to accomplish the several objects thereof in substantially the manner her inafter described and as more particularly pointed out in the claims, and reference is herein made to the accompanying; drawings that form a part of this specification.

In the drawings Figure 1, is a vertical elevation of a switch box, with its door opened to disclose my invention installed therein.

Figure 2, is a vertical fragmentary section on irregular line 22, 1, the door being shown in closed position.

Figure 3, is a view in perspective showing; a fragmentary portion of the lower right hand corner of the structure illustrated in Figure 1, with the guard plate out of normal position and still connected with the box.

The drawings represent a schematic manner, a typical or preferred form-in which my invention may be made, and in said drawings the same reference characters are employed to identify similar parts wherever they appear throughout the several views.

The box comprises sidewalls and 6, end walls 7 and 8, a back wall 9. and there is a cover or door 10 that closes the front. The cover or door is swingingly mounted upon the edge of the side wall 6 by suitable hinges laterally from forward edr'ss and its rear all 9 of face or back is secured to the rear The movable parts or rotating elcthe box. ments X, Y and Z of the switch are mounted on a square shaft ll that has hearings in opposite side walls 5 and 6 of the box, and said rotating elements have spring; clips between which fuses of any suitable type may be removahly mounted. Ii handle 16 on the exten (led end of the shaft adjacent the hinged side of the door is adapted to rotate these movable elements to brine; the fuses to a position where they may be readily accessible when the door is opened. As will be seen in the drawing, the handle 16 is so positioned that its movement from one position to another is positively prevented when the door is opened. the purpose of which will hereinafter he more fully described.

A safety will 1? in the form of a plate of insulation is mounted in front of the base element 12 and provided with spaced holes 18 to receive the studs 13 and insure the proper positionin of. the safety wall with respect to the switch mechani n. and in the upper edge of this plate there a notch or recess 19 that its around an eye 20. A pad-lock 21 has its bail or loop passed through the eye in front of the plate to maintain the safety wall in a locked position and the key of the lock is retained by the person authorized to have access to the switch parts. The lower edge of the safety wall is positioned behind the upstanding: portion of stop or fiangre extending; inwardly from the end wall 8 opposite the eye 20. Thus the safety wall may not be removed by unauthorized persons. and may be displaced from its normal position by only unlocking and removing tie padlock. Parallel elon etc-d slots or openings 24 and 25 are f rmed lil the safety wall and are slightly larger than the edge dimensions of the rotati a elci-nonts X. Y and Z of the switcln so that when the crank 16 is moved from one position to the other said rotating switch elements will be correspondingrly removed. ll hen the handle is in the position shown in Figure l and the door has been opened by persons unfamiliar with switches there are no live elements exposed, because of the fact that the p:- as X. Y and are made of heavy insulating material. .Vhen it is desired to replace a fuse the handle 16 may be moved from its shown position to its other position before opening the door and this will cause the braking of the circuit and will expose the fuse carrying clips 15 and the fuses through the apertures 23, and 25. Thus it will be obvious the handle cannot be moved from one of its positions tot-he other while the door is opened. In order to prevent the safety walls being misplaced or lost, and also for the purpose of preventing the door being closed without replacing or position ing the safety wall in its proper manner, said wall is permanently connected to the interior of the housing or box by means of a chain 26, the ends of which are secured to eyes or staples 27 and 28 respectively on the safety wall and adjacent portion of the interior of the box. Preferably this chain is disposed in the lower right hand corner as shown in the drawings and, should a person attempt to close the door without properly replacing the safety wall the edge or flange of the door will come into contact with the portion of the chain lying over the edge of the adjacent wall of the box and successfully prevent further closing movement of the door. This will im mediately direct the persons attention to his omission to replace the safety wall and it will be necessary for said wall to be properly positioned before the door of the box can be closed.

lVhat I claim is 1. In an electric switch a boxlike housing, a closure therefor, a safety 'all removably positioned within the housing and separating the live portions of the switch from the portion of the housing nearest the closure, and means connecting the safety wall to the housing, which means is adapted to be positioned between an edge of the housing and the closure when said wall is removed from its normal position whereby to prevent a closed coaction between the box and the closure.

2. In an electric switch, a box-like housing, a closure therefor, a safety wall separating the live portions of the switch from the portion of the box through which access may be had upon the removal of the closure, means for maintaining said safety wall in a normally locked position, and other means connecting said wall to the interior of the housing, which other means adapted to extend over an edge of the housing when the safety wall is removed from the housing, whereby to prevent replacement of the closure while the safety wall out of its normal position.

8. In an electric switch a box-like housing, a closure therefor, a safety wall protecting the live portions of the switch from access when the closure is removed, and a flexible element connecting the wall to the interior of the housing, said element adapted to extend over an edge of the housing when the wall is displaced, whereby to prevent replacement of the closure to its normal position, while the safety wall is displaced.

l. In an electric switch a box-like housing, a door hinged to one of the walls thereof and adapted to close the hon 1 safety wall protecting the live poi iions of the switch from access when the door opened, means for locking i wall to its normal position, and a tie: .0: element connecting said wall to the interior of the housing and adapted to extend over an edge of the housing when the wall is unlocked and removed from the housing, whereby said element is in a position to be engaged by the door and prevent closure of the latter.

5. In an electric switch a housing, a closure therefor, a safety wall protecting the live portions of the switch from access when the closure is removed, a stop on one wall of the housing back of which an edge of said safety wall is normally positioned, locking means coacting with the opposite edge of said safety wall and an adjacent housing wall, and means connecting said safety wall to the housing and adapted to be positioned between an edge of the housing and the closure when said safety wall is removed from its normal position whereby to prevent replacement of the closure, while the safety wall is displaced.

6. An electric switch construction comprising a housing, a closure hinged to the front of the housing, a movable switch mechanism including a rock-shaft, a rotatable element mounted on said shaft, and fuse terminals projecting from said element normally towards the back of the housing, a safety wall having an aperture through which said rotatable element moves when the shaft is rocked to open the switch and thereby to project the fuse terminals through said wall, a flange on said housing back of which an edge of said wall is positioned, and devices for securing an opposite edge of said wall.

7. An electric switch construction comprising a housing, a closure hinged to the front of the housing, an insulating base outstanding from the back of the housing and approaching the closure, a movable switch mechanism including a roclvshaft, journaled in said housing and extending through said base, a rotatable insulating block mounted on said shaft, and fuse terminals projecting from said block normally towards the back of the housing, a safety wall having an aperture through which said block moves when the shaft is rotated to open the switch and thereby to project the fuse terminals through said wall, the rear face of said wall resting against the forward nations of said base to prevent inward movement of the wall, and devices for reinovably maintaining said wall in position.

8. An electric switch construction comprising a housing, a closure hinged to the front of the housing, an insulating base outstandthe switch and thereby to project the fuse terminals through Silitl well, said well being disposed 2 against the forward portions of said base and having; apertures to receive said studs, and devices for remomhly mounting sui l ull in position.

Signed. at Chicago, in the county of Cook aural. State of Illinois, this 9th (hi of March, 100? MAR-TIN P. LUTHER. 

